Function

Summary

Returns a copy of a pointer object.

Package

fli

Signature

copy-pointer pointer &key type pointer-type => copy

Arguments

pointer

A pointer to copy.

type

The type of the object pointer to by pointer.

pointer-type

The type of pointer.

Values

copy

A copy of pointer.

Description

The function copy-pointer returns a copy of pointer.

Example

In the following example a pointer point1 is created, pointing to a :char type. The variable point2 is set equal to point1 using setq, whereas point3 is set using copy-pointer. When point1 is changed using incf-pointer, point2 changes as well, but point3 remains the same.

(setq point1 (fli:allocate-foreign-object :type 

                                          :char))

(setq point2 point1) (setq point3 (fli:copy-pointer point1)) (fli:incf-pointer point1)

The results of this can be seen by evaluating point1, point2, and point3.

The reason for this behavior is that point1 and point2 are Lisp variables containing the same foreign object; a pointer to a char, whereas point3 contains a copy of the foreign pointer object.

See also

make-pointer
Copying pointers